Inductive kickback protection by using multiple parallel circuit breakers with downstream tvs diodes

ABSTRACT

Embodiments of the present invention disclose an apparatus including a power source and a plurality of electronic subsystems connected in parallel to the power source. Each of the plurality of electronic sub systems includes a circuit breaker, a transient-voltage-suppression (TVS) diode, and a load. The TVS diode is located downstream of the circuit breaker in each of the plurality of electronic systems.

BACKGROUND

The present invention relates generally to the field of electronicsystems, and more particularly to the protection of system powerintegrity and protection of active devices from being damaged when ashort occurs.

In a high availability, redundant electronic system, solid state circuitbreakers are commonly used to protect the system as a whole from shortcircuits on individual components within the system. There will be amain power source running through the system. Active devices that arecapable of failing (shorting) must not be placed directly on the mainpower source. This prevents a short on a device from taking down themain power source, thus taking down the entire system. All activeelectronic components are instead placed downstream of circuit breakers.If one of these active components fails (shorts), the circuit breakerwill trip and only those devices downstream of that particular circuitbreaker will lose power. All remaining devices that are downstream ofother circuit breakers will remain functional.

BRIEF SUMMARY

Additional aspects and/or advantages will be set forth in part in thedescription which follows and, in part, will be apparent from thedescription, or may be learned by practice of the invention.

Embodiments of the present invention disclose an apparatus including apower source and a plurality of electronic subsystems connected inparallel to the power source. Each of the plurality of electronicsubsystems includes a circuit breaker, a transient-voltage-suppression(TVS) diode, and a load. The TVS diode is located downstream of thecircuit breaker in each of the plurality of electronic subsystems.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certainexemplary embodiments of the present invention will be more apparentfrom the following description taken in conjunction with theaccompanying drawings, in which:

FIG. 1 illustrates a circuit diagram of an electronic system for where atransient-voltage-suppression (TVS) diode is upstream of a circuitbreaker of a subsystem.

FIG. 2 illustrates the path of inductive kickback energy when a circuitbreaker is tripped in an electronic subsystem.

FIG. 3 illustrates a circuit diagram of an electronic system where a TVSdiode is downstream of a circuit breaker of a subsystem, in accordancewith an embodiment of the present invention.

FIG. 4 illustrates the path of inductive kickback energy when a circuitbreaker is tripped in electronic subsystem, where the TVS diode isdownstream of a tripped circuit breaker, in accordance with anembodiment of the present invention.

FIG. 5 illustrates a kick back voltage when a plurality of circuitbreakers are tripped in electronic subsystem, where the TVS diode isdownstream of a tripped circuit breaker, in accordance with anembodiment of the present invention.

DETAILED DESCRIPTION

The following description with reference to the accompanying drawings isprovided to assist in a comprehensive understanding of exemplaryembodiments of the invention as defined by the claims and theirequivalents. It includes various specific details to assist in thatunderstanding but these are to be regarded as merely exemplary.Accordingly, those of ordinary skill in the art will recognize thatvarious changes and modifications of the embodiments described hereincan be made without departing from the scope and spirit of theinvention. In addition, descriptions of well-known functions andconstructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are notlimited to the bibliographical meanings, but, are merely used to enablea clear and consistent understanding of the invention. Accordingly, itshould be apparent to those skilled in the art that the followingdescription of exemplary embodiments of the present invention isprovided for illustration purpose only and not for the purpose oflimiting the invention as defined by the appended claims and theirequivalents.

It is to be understood that the singular forms “a,” “an,” and “the”include plural referents unless the context clearly dictates otherwise.Thus, for example, reference to “a component surface” includes referenceto one or more of such surfaces unless the context clearly dictatesotherwise.

Reference will now be made in detail to the embodiments of the presentinvention, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to like elementsthroughout. Embodiments of the invention are generally directed to anelectronic system for the prevention of power supply shutdown andprevention of damage to electronic devices caused by inductive kickbackwhen a circuit breaker trips (due to a downstream component short). Whenmultiple subsystems are connected to a power source in parallel, whereineach of the subsystems comprises at least a circuit breaker, atransient-voltage-suppression (TVS) diode, and a load. The TVS diode andthe load are located downstream of the circuit breaker. When a circuitbreaker trips (due to a downstream short) a kickback voltage is created,caused by the parasitic inductance between the circuit breaker and powersupply and the sudden decrease in current though this inductance. Thiskickback energy is dissipated through the TVS diodes of other subsystemsthat are connected in parallel, thus preventing damage to any of thesubsystems when a circuit breaker trips. All of this happens without therisk of having the fallible TVS diodes upstream of the circuit breakers.This prevents a short of a TVS from causing the entire system to losepower.

FIG. 1 illustrates a circuit diagram for an electronic system for when atransient-voltage-suppression (TVS) diode is upstream of a circuitbreaker of a subsystem. The electronic system 100 includes a powersource 110, a parasitic inductance 140, and a plurality of subsystems120A to 120N connected in parallel. Each of the plurality of subsystems120A, 120B, 120C to 120N includes a transient-voltage-suppression (TVS)diode 122A, 122B, 122C to 122N, a circuit breaker 124A, 124B, 124C to124N, and a load 126A, 126B, 126C to 126N. Load 126A, 126B, 126C to 126Ncan be, for example, any type of electronic component, circuit componentor device that draws power from the power source 110 via the circuitconnected to the subsystems 120A, 120B, 120C to 120N, respectively. Theload 126A, 126B, 126C to 126N is located in parallel with each of theTVS diodes 122A, 122B, 122C to 122N, respectively.

TVS diodes 122A, 122B, 122C to 122N are solid state pn junction devicesspecifically designed to protect sensitive semiconductors from damagingeffects of transient voltages. The electrical characteristics of thedevice are determined by factors such as junction area, dopingconcentration, and substrate resistivity. The surge power and surgecurrent capability of the TVS diode 122A, 122B, 122C to 122N areproportional to the junction area. TVS diodes 122A, 122B, 122C to 122Nare constructed with large cross sectional area junctions for absorbinghigh transient currents. When the normal operating voltage of theprotected circuit is exceeded, the TVS diode 122A, 122B, 122C to 122Njunction avalanches providing a low impedance path for the transientcurrent. As a result, the transient current is diverted away from theprotected components and shunted through the TVS diodes 122A, 122B, 122Cto 122N. The TVS diodes 122A, 122B, 122C to 122N return to highimpedance state after the transient threat passes.

The electronic system 100 of FIG. 1 illustrates a plurality ofsubsystems 120A, 120B, 120C to 120N connected in parallel to a powersource 110. Subsystem 120B will be discussed in more detail as anexample and the other subsystems have a similar configuration. Subsystem120B includes a TVS Diode 122B upstream of a circuit breaker 124B and aload 126B.

The electronic system 100 of FIG. 2 illustrates a plurality ofsubsystems 120A, 120B, 120C to 120N connected in parallel to a powersource 110, when the a device in the load shorts and the circuit breaker124B trips.

The tripping of one circuit breaker 124B does, however, cause a negativeeffect on the input of all of the other subsystems 120A, 120C to 120N.The negative effect is called inductive kickback 130. There will alwaysbe some parasitic inductance 140 between the power source 110 and thecircuit breaker 124B. If the load 126B downstream of a circuit breaker124B is pulling energy from the power source 110 (through the parasiticinductance 140), and that circuit breaker 124B trips do to a short,inductive kickback 130 will happen at the input 150 of the subsystems120A, 120B, 120C to 120N. This results in a temporary voltage spike.This temporary voltage spike may damage devices in the other subsystems.TVS diode 122B will channel most of the energy of the voltage spike toground and maintain a constant voltage on the inputs 150 to thesubsystems 120A, 120B, 120C to 120N, thus preventing damage. The problemwith this implementation is that the TVS diode 122B itself can fail(short). Since it is upstream of the circuit breaker 124B, a failure ofthe TVS diode 122B can take out the power source 110 and therefore theelectronic system 100. As illustrated by FIG. 2, circuit breaker 124Btrips, an inductive kickback 130 is created and is dissipated throughTVS diode 122B of the same subsystem 120B.

FIG. 3 illustrates a circuit diagram for an electronic system when a TVSdiode is downstream of a circuit breaker of a subsystem, in accordancewith an embodiment of the present invention. FIGS. 4 and 5 illustratesan inductive kick back when a circuit breaker is tripped in anelectronic system, when the TVS diode is downstream of the circuitbreaker, in accordance with an embodiment of the present invention.

The electronic system 300 of FIGS. 3, 4 and 5 have a similar set up asthe electronic system 100 of FIGS. 1 and 2. The electronic system 300includes a power source 310, a parasitic inductance 340, and a pluralityof subsystems 320A to 320N connected in parallel. Each of the pluralityof subsystems 320A, 320B, 320C to 320N includes atransient-voltage-suppression (TVS) diode 322A, 322B, 322C to 322N, acircuit breaker 324A, 324B, 324C to 324N, and a load 326A, 326B, 326C to326N. TVS diodes 322A, 322B, 322C to 322N are located downstream of eachof their respective circuit breakers 324A, 324B, 324C to 324N.

Subsystems 320A, 320B, 320C to 320N are connected in parallel to thepower source 310. For example, when circuit breaker 324B trips, aninductive kickback 330, also known as a kickback voltage, is generatedat the input 350 of the subsystems 320A, 320B, 320C to 320N, but sincethe TVS diode 322B is located downstream of the circuit breaker 324B itdoes not dissipate the inductive kickback 330. Instead the inductivekickback 330 at the input 350 to the subsystems 320A, 320B, 320C to 320Nis distributed to the parallel subsystems. As illustrated by FIGS. 4 and5, the inductive kickback 330 at the input 350 to the subsystems 320A,320B, 320C to 320N is distributed to one or a plurality of thesubsystems 320A, 320C to 320N. The path of the inductive kickback 330 isdistributed to subsystems that have not failed. As illustrated by FIG.5, if the circuit breakers 324B and 324C of subsystems 320B and 320Chave tripped then the inductive kickback 330 is dissipated by subsystemsthat have not experienced a failure of their circuit breakers. The powerto system 310 is not interrupted and the voltage at the input to thesubsystems 320A, 320B, 320C to 320N is held below a point that candamage other devices in system 300. If a TVS diode 322B fails (shorts),the same event happens. The power to system 300 is not interrupted andthe voltage at the input 350 to the subsystems is held below a pointthat can damage other devices in system 300.

While the invention has been shown and described with reference tocertain exemplary embodiments thereof, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the spirit and scope of the presentinvention as defined by the appended claims and their equivalents.

The descriptions of the various embodiments of the present inventionhave been presented for purposes of illustration, but are not intendedto be exhaustive or limited to the embodiments disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of the describedembodiments. The terminology used herein was chosen to best explain theprinciples of the one or more embodiment, the practical application ortechnical improvement over technologies found in the marketplace, or toenable others of ordinary skill in the art to understand the embodimentsdisclosed herein.

What is claimed is:
 1. An apparatus comprising: a power source; and aplurality of electronic subsystems connected in parallel to the powersource; wherein each of the plurality of electronic subsystems includesa circuit breaker, a transient-voltage-suppression (TVS) diode, and aload; and wherein the TVS diode is located downstream of the circuitbreaker in each of the plurality of electronic subsystems.
 2. Theapparatus of claim 1, wherein the load is located downstream of thecircuit breaker in each of the plurality of electronic subsystems. 3.The apparatus of claim 1, wherein the load is located in parallel withthe TVS diode in each of the plurality of electronic subsystems.
 4. Theapparatus of claim 1, wherein when the load of one of the plurality ofelectronic subsystems fails to a short, the circuit breaker in thatsubsystem trips causing inductive kickback; and wherein the inductivekickback is dissipated through at least one of the parallel electronicsubsystems.
 5. The apparatus of claim 1, wherein the inductive kickbackis dissipated through a plurality of the parallel connected electronicsystems.
 6. The apparatus of claim 1, wherein when a plurality ofcircuit breakers in multiple of the plurality of electronic system failsan inductive kickback is generated; wherein the inductive kickback isdissipated through another of the parallel connected electronic systems.7. An electronic system comprising: a power source; and a plurality ofsubsystems connected in parallel to the power source; wherein each ofthe plurality of subsystems includes a circuit breaker, atransient-voltage-suppression (TVS) diode, and a load; and wherein theTVS diode is located downstream of the circuit breaker in each of theplurality of subsystems.
 8. The electronic system of claim 7, whereinthe load is located downstream of the circuit breaker in each of theplurality of subsystems.
 9. The electronic system of claim 7, whereinthe load is located in parallel with the TVS diode in each of theplurality of subsystems.
 10. The electronic system of claim 7, whereinwhen the load of one of the plurality of electronic subsystems fails toa short, the circuit breaker in that subsystem trips causing inductivekickback; and wherein the inductive kickback is dissipated through atleast one of the parallel electronic subsystems.
 11. The electronicsystem of claim 7, wherein the inductive kickback is dissipated througha plurality of the parallel connected subsystems.
 12. The electronicsystem of claim 7, wherein when load of a plurality of the plurality ofelectronic subsystems fails to a short, the circuit breaker in each ofthe subsystem trips causing inductive kickback; wherein the inductivekickback is dissipated through another of the parallel connectedsubsystems.
 13. A method for managing power surges in an electroniccircuit, comprising: arranging a plurality of electronic subsystems forconnection in parallel to a power source, each of the plurality ofelectronic subsystems includes a circuit breaker, atransient-voltage-suppression (TVS) diode, and a load; and locating theTVS diode downstream of the circuit breaker in each of the plurality ofelectronic subsystems.
 14. The method of claim 13, wherein the load islocated downstream of the circuit breaker in each of the plurality ofelectronic subsystems.
 15. The method of claim 13, wherein the load islocated in parallel with the TVS diode in each of the plurality ofelectronic subsystems.
 16. The method of claim 13, wherein when the loadof one of the plurality of electronic subsystems fails to a short, thecircuit breaker in that subsystem trips causing inductive kickback; andwherein the inductive kickback is dissipated through at least one of theparallel electronic subsystems.
 17. The method of claim 13, wherein theinductive kickback is dissipated through a plurality of the parallelconnected electronic systems.
 18. The method of claim 13, wherein when aplurality of circuit breakers in multiple of the plurality of electronicsystem fails an inductive kickback is generated; wherein the inductivekickback is dissipated through another of the parallel connectedelectronic systems.